1. Field of the Invention
The present invention relates to an image forming apparatus and a maintenance method, and more particularly to maintenance technology for conveyance members which hold and convey a recording medium.
2. Description of the Related Art
As a general image forming apparatus, it is suitable to use an inkjet recording apparatus, which forms a desired image on a recording medium by ejecting and depositing a plurality of colors of inks onto the recording medium from a plurality of nozzles provided in an inkjet head. In the inkjet recording apparatus, the recording medium is held and conveyed by, for example, a drum conveyance method or a belt conveyance method. In the drum conveyance method, the recording medium is held on the outer circumferential surface of a conveyance member having a drum shape, and the recording medium is conveyed with rotation of the drum. In the belt conveyance method, the recording medium is held on the surface of an endless belt that is wrapped about a plurality of rollers, and the recording medium is conveyed with rotation of the rollers. As the method of holding the recording medium on the conveyance member, one of various methods is used appropriately in accordance with the composition of the apparatus: such as a vacuum suction method, in which the recording medium is fixed and held by a suction pressure applied through suction holes arranged in the surface of the conveyance member on which the recording medium is held from the inner side of the conveyance member; an electrostatic attraction method, which uses static electricity; a method which uses a mechanical holding member; and the like.
Japanese Patent Application Publication No. 10-175338 discloses a structure in which a rotatable drum has a plurality of suction holes passing through the outer circumferential surface from the inner side of the drum to the outer side, a porous sheet is attached to the outer circumferential surface of the drum, and the recording medium is held by suction through the pores of the porous sheet and the suction holes. However, in fixing a recording medium in the vacuum suction device with no cleaning mechanism as in Japanese Patent Application Publication No. 10-175338, when ink mist, paper dust, or the like, becomes filled into the vacuum flow channels, it is not possible to fix the recording medium stably in position.
In an inkjet recording apparatus, ink may become attached to the recording medium conveyance members, due to scattering of the ink during image formation or the ejection of ink onto the edge portions of the recording medium when forming borderless images. Further, paper dust and other dirt may adhere to the recording medium conveyance members in addition to ink. In order to remove adhering material such as ink of this kind, a cleaning member is provided.
Japanese Patent Application Publication No. 06-320754 discloses an inkjet recording apparatus that includes a cylindrical paper feed device, which conveys a recording medium, and a blade, which makes contact with the circumferential surface of the paper feed device and wipes and cleans the paper feed surface in conjunction with the rotation of the paper feed device. However, due to the fact that the cleaning device is of a sliding type, the abrasion of the blade causes rapid wear when the conveyance speed is fast, and hence this method cannot be regarded as suitable for high-speed printing. Moreover, as wearing of the blade progresses, there is a problem in that sufficient cleaning cannot be carried out.
Further, if cleaning using a blade is employed for a recording medium conveyance member (paper feed device) having holes arranged in the surface that holds the recording medium as in Japanese Patent Application Publication No. 10-175338, then although it is possible to remove the adhering material that is adhering to the surface holding the recording medium and the periphery of the holes, it is difficult to remove adhering material that has entered into the holes. Furthermore, when the blade passes over the holes, the adhering material that has become attached to the blade may enter into the holes and hence there is a concern with regard to blocking of the holes.